Transcript Slide 1
Remember…
• Continental drift
• Plate tectonics
• Which movement causes earthquakes?
Earthquake City
• You are going to build a city
• The city will be put through simulated
(fake) earthquakes to see which structures
withstand the shaking the best.
Background…
• When there is an earthquake, energy
travels through the earth and can cause
damage to buildings and other structures
far away.
• The amount of damage caused by an
earthquake depends on several things
such as the strength of the earthquake,
how long it lasts, and where it happens.
Background…
• The epicenter of an earthquake is the
point on the earth's surface directly above
where an earthquake starts, or where the
shaking begins.
• The damage will typically be the greatest
at the epicenter.
Background
• Today, some buildings are made of more
flexible materials so that they bend and
sway during an earthquake and do not fall
down as easily.
• We are going to experiment with different
“building materials” and see which are the
best
Step One
• Go get 25 sugar cubes
• Build 5 sugar cube skyscrapers, each five
sugar cubes tall .
• Build them at the following intersection:
– A1
– B2
– C3
– D4
– E5
• Now start tapping LIGHTLY on the corner
with the eraser of a pencil.
• Continue to tap until at least one cube
from each skyscraper falls.
• How many taps did it take for a cube to
fall?
Fill in the table
Location of
Building
Location of
Earthquake
Epicentre
Hard or soft
vibrations?
How many taps?
A1
A1
Soft
?
“
“
A1
Medium
C3
• Now rebuild your towers at the same
locations.
– A1, B2, C3, D4, E5
• Now tap again, but this time a bit harder.
• Record answers
• Now rebuild your towers at the same
locations again.
– A1, B2, C3, D4, E5
• Now tap again, but this time a LOT harder.
• Record answers
Supercity!
• Now you are going to build you own
supercity!
• 5 buildings, each with 5 pieces
• Sugar cubes= bricks
• Crackers= wood
• Bouillon cubes= hay stacks
• Jello= mortar
• Caramel= Cement
Groups
•
•
•
•
•
•
Natalie, Cleefton, Andrew, Yousif
Abdulaziz, Austin, Buay, Roland
Jeny, Connor, Miranda, Basique
Keanu, Kris, Cody
Fanta, Egeh, Hassan
Cassandre, Logan, Alex
Earthquakes
• Shaking and trembling of the earth’s crust.
• About 8000 occur every day or one every 11
seconds
• Caused by plates sliding beside each other
(sliding/transform)
• Tsunami - earthquake on the ocean floor: causing
waves to become greater than 20 meters high
Faults
• Faults are weaknesses in the rock and
therefore earthquakes tend to happen over
and over along the same faults.
Most major faults in the United
States, particularly in California,
are what are known as strike-slip
faults.
A strike-slip fault is
formed where two
parts of the earth’s
crust (plates) slide
past each other.
Thrust Fault
A thrust fault occurs
when the plate moves
in an
upward motion.
Normal Fault
Normal plate
movement
is slipping in a
downward
motion.
Seismic Waves
• The three main types
of seismic waves are:
P waves, S waves,
and L waves
Seismic Waves
…are waves of energy that
travel through the Earth as a
result of an earthquake
P Waves
• Primary waves
• Fastest waves
• Arrive first at the
epicenter
S Waves
• Secondary waves
• Move in up-down
motion
L Waves
• Slowest moving seismic waves
• Travel on top of Earth’s surface
Measuring Earthquakes
• Seismograph-measures
and detects seismic
waves
• Richter Scale- a scale
that allows scientists to
determine earthquake
strength
• 1-10 levels at which an
earthquake is measured.
Above a 6 is very
destructive
Measuring Earthquakes
• Epicentre: the point
on the Earth's surface
that is directly above
the centre of the
earthquake
• Most violent shaking
happens at the
epicenter
WHAT INFLUENCES THE AMOUNT OF
DAMAGE AN EARTHQUAKE CAUSES?
- Magnitude of the earthquake (how it is)
- Distance of location from epicentre of the earthquake
- Type of movement of the plates or along fault
- Soil conditions (loose, solid, flexible, stiff)
- Construction type and quality of buildings